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Care of Sea Oats Grass

Sea oats grass (Chasmanthium) is an ornamental grass native to the coast lines of Eastern North America, growing from 3 to 5 feet tall and 2 to 3 feet wide. Sea oats grass is an upright, clumping plant that has dangling green flowers in the summer. The grass turns a shade of copper in late summer and autumn. This grass can grow in any light conditions and in many different soil conditions, including clay, sand, dry or moist soils, but it prefers a neutral pH. Because sea oats grasses grow tall, you can plant them as a border, as a background planting, as a privacy screen or in containers.

Space your sea oats grass 2 to 3 feet apart. Although the grass is adaptable to many different soils, plant it in well-draining soil for best growth.

Water the sea oats grass once or twice each week during the first growing season. This will help the roots to grow and the plant to become established.

Feed the sea oats grass ¼ cup of slow-release 10-10-10 NPK (Nitrogen-Phosphorous-Potassium) fertilizer each year in the spring, just as the grass begins to grow again. Water the grass thoroughly immediately after applying the fertilizer.

Divide the sea oats grass in the early spring to thin out the clumps when needed. You can dig up and divide the clumps of grass, and then replant them in other locations in your landscape.

Water the sea oats grass once every two weeks during the growing season from the second year onward. Water the grass more frequently to replace rainfall during times of drought or prolonged dry spells.


If you want your sea oats grass to be a darker shade of green, plant it in the shade. If you prefer a lighter shade of green, plant it in full to partial sunlight.


Don’t plant sea oats grass outdoors in the ground if your area experiences minimum winter temperatures below -15 degrees F. Sea oats grasses grow best in USDA Hardiness Zones 5 though 9.

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